When you've doubled your genes, what's 1 chromosome more or less?

EurekAlert: "For animals, an extra chromosome can result in major problems, but plants are another matter. Many plants can survive an extra copy of their entire genome (polyploidy), and this process often results in a new species, making it an important mechanism in evolution. In fact, over 80 percent of plants may be a product of polyploidy. This research examines how polyploidy and genomic change can lead to evolutionary change, and affect plants' fitness and vigor."